Intolerance or pseudoallergy is an adverse reaction with symptoms similar to these of an allergic reaction.
The difference between food allergy and intolerance is that allergic reactions engage the immune system whilst intolerances do not (Harvard, 2011). According to research results studied by Rich et al. (2019), intolerance mostly occurs by:
During an allergic reaction upon exposure to allergens, inflammatory mediators (e.g., histamine) are released due to the antibody of immunoglobulin E (IgE) and cause various symptoms “ranging from localized oral itching to anaphylaxis” (ibid.). The body’s immunological mechanisms are not triggered by food intolerance. The most common symptoms of food intolerance include “heartburn, cramps, belly pain, or diarrhoea” (U.S. National Library of Medicine, 20222). These reactions are usually triggered by “corn products, cow’s milk, and dairy products (lactose intolerance), wheat, and other grains that contain gluten (coeliac disease)” (ibid.). More severe symptoms include “coeliac disease or food protein-induced enterocolitis syndrome” (Rich et al., 2019).
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